Manufacture of MgO-based β"-alumina sintered bodies

Abstract

A process for manufacturing MgO-based β"-alumina sintered bodies from a starting powder comprising an MgO-based β"-alumina as a main ingredient, through shaping and firing, in which process shaped bodies before firing contain 0.3˜5 wt. %, preferably 1˜3 wt. %, of Na aluminate. The resulting sintered bodies are high in density, ionic conductivity and strength and useful for solid electrolytes, for example, of sodium sulfur cells.

What is claimed is: 
     
       1. A method of producing an MgO-based β"-alumina sintered body, comprising the steps of: shaping a starting powder comprising MgO-based β"-alumina and 0.3˜5.0 wt. % of sodium aluminate into a body; and   firing the shaped body to produce a sintered body.   
     
     
       2. The method of claim 1, wherein the amount of sodium aluminate is 1.0-3.0 wt. %. 
     
     
       3. The method of claim 1, wherein the shaped body is fired at a temperature ranging from 1550°-1650° C. for 0.5-2.0 hours. 
     
     
       4. The method of claim 1, wherein the sintered body has an ionic conductivity ranging from 0.20-0.30/Ωcm and a four-point flexural strength ranging from 210-280 MPa.